What Twitter Gains by Expanding the 140-Character Tweet

Twitter Inc. CEO Jack Dorsey had something to say on Tuesday that couldn’t be boiled down to a tweet-sized 140 characters. He posted the 1,317-character statement on Twitter anyway, as a photo.

Mr. Dorsey was making a point with the awkward screenshot. What if the text of his letter could fit into a tweet? It could be searched and highlighted by users, he wrote, in a soft defense of why Twitter might do the unthinkable: expanding the character limit up to 10,000.

But Mr. Dorsey’s act of posting the long response on Twitter made a less explicit point: This coming change is also about keeping content under the Twitter roof. Thousands of people were forced to stay on Twitter or travel to the site to read his note.